Pharmaceutical preparations which provide a dosage form of Tamoxifen are known the dosage form being solid, viz. tablets having strengths of the medicinally active ingredient of from 10 mg Tamoxifen. The Tamoxifen regularly is present in the form of the corresponding citrate, ethanamine, 2-4-(1,2-diphenyl-1-butenyl)phenoxy)-N,N-dimethyl-(Z)-,2-hydroxy-1,2,3-pro panetricarboxylate (1:1), the IUPAC name of which is (Z)-2-[4-(1,2)-Diohenylbut-1-enyl)phenoxy]ethyldimethylamine citrate.
Although the known tablets are generally acceptable as far as their medicinal activity is concerned, the solid dosage form imposes restrictions on the pharmaceutical use of Tamoxifen. Some patient populations have a difficulty, physical or psychological, in swallowing solid dosage forms. If a liquid dosage form were available, these patients could more easily take the required dose of Tamoxifen, having it administered in the form of an oral liquid preparation or, e.g., by means of a naso-gastric tube.
However, such oral liquid preparations of Tamoxifen are neither available on the market, nor even known in the art. To manufacture a liquid preparation of Tamoxifen presents a problem to the person skilled in the art, as the compound has a poor solubility in pharmaceutically acceptable solvents and in view of the general difficulty in predicting the solubility of specific pharmaceutical salts such as Tamoxifen Citrate in any given liquid.